Is EQ-5D-5L better than EQ-5D-3L? A comparison of descriptive systems and utility scores in patients with kidney chronic disease

OBJECTIVE: To compare the psychometric performance and interchangeability of the EQ-5D-3L and EQ-5D-5L in a Spanish cohort of patients with chronic kidney disease using real-world data. METHODS: 170 patients completed the generic EQ-5D-3L, EQ-5D-5L, and SF-12 v2, and the specific KDQOL-SF v1.3. The psychometric properties assessed included feasibility, ceiling effect, construct validity (convergent and known-group validity), and informativity. Interchangeability between both versions was examined via inconsistency rates and levels of agreement. RESULTS: Both versions demonstrated excellent feasibility (< 0.6% missing data). The overall ceiling effect was identical (28.2%), but the EQ-5D-5L showed reduced ceiling effects across four dimensions—especially mobility—suggesting better discriminatory power. The EQ-5D-3L demonstrated slightly stronger construct validity, with 75% of the predefined hypotheses confirmed versus 69% for the EQ-5D-5L. The EQ-5D-5L exhibited greater absolute informativity across all dimensions [percent increase from the EQ-5D-3L to the EQ-5D-5L: mobility (81.29%), self-care (24.22%), usual activities (48.08%), pain/discomfort (47.87%), anxiety/depression (27.48%)], and greater relative informativity in three dimensions [mobility (23.75%), usual activities (1.08%), pain/discomfort (0.94%)]. Inconsistencies were infrequent (6%) and mostly mild (level 1: 5.6%). Agreement was“almost perfect” (concordance correlation coefficient: 0.858; 95%CI: 0.816–0.891). However, the mean utility was greater for EQ-5D-5L (0.783±0.229) than for EQ-5D-3L (0.738±0.274), raising concerns about interchangeability. CONCLUSIONS: The EQ-5D-3L and EQ-5D-5L are not interchangeable in patients with chronic kidney disease. The EQ-5D-5L version showed slightly better psychometric properties, particularly in informativity. Given these advantages, the EQ-5D-5L is the preferred instrument for assessing health-related quality of life and conducting health economic evaluations in those patients.